Catheters are well known medical devices used to facilitate various medical procedures, such as diagnostic or delivery procedures. Catheter tubes are inserted into a body of a patient for various medical procedures. For example, a catheter may be used in performing diagnostic procedures such as removing a sample from a body site of a patient. Furthermore, a catheter may be inserted into an arm of the patient so that various fluids can be introduced to the patient's venous system.
Generally, a catheter has a tube portion which is relatively stiff axially and radially to allow proper placement of the catheter in the patient's body. The catheter tip is inserted into the skin, organ wall, etc. by use of a needle that is coupled to the catheter. Once the catheter has been inserted to a desired placement, e.g., in a vein
In a particular cavity, etc, of an organ, the needle is removed leaving the end of the catheter (the tube portion) situated in the desire placement.
In this regard, catheters are to convey fluids into and out of body cavities besides veins. For example, catheters are often placed into arteries to measure blood pressure or remove arterial blood for analysis of gases reflecting lung function;
catheters are placed into the peritoneum (the space surrounded by the peritoneal membrane and external to organs in the abdomen) to perform peritoneal dialysis and remove fluids and toxins from the patient. And other catheters are placed into the fluid around the nervous system (cerebral spinal fluid) for removal of this fluid or administration of drugs, and into the subcutaneous space for administration of various drugs or fluids. Catheters are subject to infection and to other problems.
Depending upon the use and application of the catheter, the size of the catheter, i.e., the diameter of the tube, including the openings, varies. In this regard, catherers come in various sizes or “gauges,” as it is termed in the art. In some applications, for example for the delivery of blood in transfusions, the catheter may need to be a 14- or 16-gauge catheter, and in the delivery of medicines to the venous system of a patient, the catheter mar need to be a 20- or 22-gauge catheter,
Note that the smaller the diameter of the catheter, the larger the gauge.
Therefore, a 22-gauge catheter is smaller than a 14-gauge catheter. The greater the diameter, the more fluid that can be delivered through the catheter. To deliver large amounts of fluid, a healthcare provider uses a 14 or 16-gauge catheter. To administer medications, a healthcare provider uses an 18- or 20-gauge catheter.
If a catheter is initially inserter in a patient's vein through which to deliver blood, e.g., for a transfusion (where typically a 14- or 16-gauge catheter would be used), the same catheter cannot be used to also deliver needed medication. In this regard, to deliver the needed medication to the patient, a smaller gauge catheter would be necessary, e.g., a 22- or 24-gauge catheter. In such a scenario, the healthcare provider would be required to re-stick the patient with a new needle to deliver a smaller gauge catheter to a vein in order to effectively create a port through which the medicine could be delivered to the vein.